Tips for Buying an Insulin Pen

Using an insulin pen can take the hassle out of injecting. Here’s what you should keep in mind.

Find the Best Pen for You

For kids and very insulin-sensitive adults: Look for a pen that allows for 0.5-unit insulin doses. Most pens dose in 1-unit increments.

For those with dexterity issues: Consider the placement of a pen’s dosing button—some may make dosing easier than others.

For the ouch averse: Some pens use spring-loaded mechanisms that make injecting less painful, says Kellie Antinori-Lent, MSN, RN, ACNS-BC, BC-ADM, CDE, a diabetes clinical nurse specialist at the University of Pittsburgh Medical Center–Shadyside Hospital.

Pen Needles: What to Know

Needles vary in length and thickness. Needle length can range from 4 to 12.7 millimeters, though most are 4 or 5 millimeters long. The thickness of the needle is measured by gauge (most are between 29 and 33). The lower the gauge, the thicker the needle. Shorter, thinner needles may feel more comfortable, but thicker needles make it possible to deliver a larger dose of insulin more quickly. If you find insulin leaks out after an injection, a longer needle may be best for you—it will inject deeper into the tissue and reduce leakage. Technique can also affect what you feel upon injection, says Antinori-Lent.

How to Inject:

Prepare the skin. Clean the area with alcohol, if possible, then wait for it to dry.

Prime the pen. To ensure accurate dosing, place a new needle onto the pen and hold the pen with the needle pointing up. Dial 2 units, then push the button until the dose indicator hits zero. Repeat (if necessary) until you see insulin at the needle tip. If no insulin appears, replace the needle and repeat.

Check the pen for air bubbles (air displaces the insulin, which could cause a dosing error). Hold the pen with the needle pointing upward and gently tap the cartridge a few times.

Inject at a 90-degree angle. If you’re using a longer needle, consider a gentle two-finger pinch to the skin to avoid injecting into the muscle. Push the dose button; make sure the counter returns to zero. Hold for five to 10 seconds, then withdraw the needle from the skin. Remove the needle from the pen and cover the pen.

The abdomen is the preferred injection site—as long as you are 2 inches away from the navel—because it’s easy to see and reach. The outer thighs, back of the upper arms, and upper buttocks are also good options. Site rotation is crucial. For guidance, see our article on injection site rotation.

Change the needle before each injection. With use, needles become dull, causing pain. To prevent air from getting into the pen reservoir and to maintain sterility, avoid leaving a needle on your pen after use. If you have a particular needle you prefer, be sure to ask your physician to specify it on your prescription, which should also say “brand necessary” and “do not substitute,” says Antinori-Lent. (Keep in mind: That may cost more.) A standardized pen needle should fit all pen devices. To be certain, check with your pharmacist, health care provider, or diabetes educator before you purchase needles.

Safety Notes

Never share insulin pens with someone else. Even if you replace the needle, you risk spreading harmful bacteria and viruses. Likewise, never share insulin pen needles.

Whichever needle you go with, do not wipe it with an alcohol pad before using. “All needles are lubricated with a coating to allow needles to glide in during injecting,” says Antinori-Lent. That quick once-over with an alcohol wipe removes the coating.